1. Field of the Invention
This invention relates to a vibration switch, more particularly to a vibration switch with an axially extending deflectable electric contact body which anchors at one end to an electric contact terminal and which is deflected at the other end when jerked to contact another electric contact terminal so as to make an electrical connection between the electric contact terminals.
2. Description of the Related Art
Referring to FIGS. 1 and 2, a conventional vibration switch 1 is shown to include a housing 101 with a through hole 103 in an end wall 102 thereof, and a first electric contact terminal 104 with a contact end which is inserted into an accommodation chamber 105 in the housing 101 via the through hole 103. An insulating plug member 108 is fittingly inserted into an opening end 109 of the housing 101, and has a recess 110 for positioning the contact end of the first electric contact terminal 104. An electric contact biasing member 106 is disposed in the accommodation chamber 105, and surrounds the contact end of the first electric contact terminal 104. A rod-shaped second electric contact terminal 107 is formed integrally with and extends from the biasing member 106, and extends outwardly of the accommodation chamber 105 through a hole 111 in the plug member 108. Once the housing 101 is jerked, the biasing member 106 is deflected to contact with the contact end of the first electric contact terminal 104 so as to make an electrical connection between the first and second electric contact terminals 104,107.
However, since the second electric contact terminal 107 is formed integrally with the biasing member 106, the following drawbacks arise:
1. The biasing member 106 and the second electric contact terminal 107 are formed from a thin metal wire of a diameter about 0.15 mm. Thus, the terminal 107 is liable to break and deform.
2. The soldering operation of the terminal 107 on a support, such as a PCB (printed circuit board), is inconvenient to conduct.
3. When the vibration switch 1 is used in a moist place, the biasing member 106 is liable to oxidize, thereby resulting in unstable electrical connection of the terminals 104,107.
4. To ensure the sensitivity of the biasing member 106, the dimension of the biasing member 106 is limited, thereby making it difficult to position the terminal 104 precisely so as to space the terminal 104 apart from the biasing member 106 in radial directions.
The object of the present invention is to provide a vibration switch which has an electric contact terminal that is not liable to deform and break, and that can be conveniently soldered onto a support, and which can provide a stable electrical connection between two electric contact terminals.
According to this invention, the vibration switch includes a housing which is adapted to be mounted on a support in an upright direction, and which has first and second side walls spaced apart from each other in a longitudinal direction transverse to the upright direction, and a surrounding wall interposed between and cooperating with the first and second side walls to confine an accommodation chamber. A first electric contact terminal has a first connecting end which extends in the upright direction and which is adapted to be connected to the support, and a first contact end which extends from the first connecting end into the accommodation chamber and which is disposed proximate to the first side wall. A second electric contact terminal is disposed to be electrically insulated from the first electric contact terminal, and has a second connecting end which extends in the upright direction and which is adapted to be connected to the support, and a second contact end which extends from the second connecting end in the longitudinal direction and into the accommodation chamber, which is disposed adjacent to the second sidewall, and which is spaced apart from the first side wall. A deflectable electric contact body is disposed in the accommodation chamber, and has an anchoring end which anchors on and which is electrically connected to the first contact end, and a deflectable segment which extends from the anchoring end along an axis in the longitudinal direction towards the second side wall and which terminates at a contact terminal end. The deflectable segment is made from a material with a biasing force such that, by means of the biasing force against weight of the deflectable segment, the contact terminal end is held along the axis so as to be spaced apart from the second contact end in radial directions relative to the axis. When the housing is jerked, the contact terminal end is deflected in the radial directions as a result of an inertial force of the deflectable segment so as to contact the second contact end, thereby making an electrical connection between the first and second electric contact terminals.